Method and apparatus for solvent extraction



Jan. 20, 1953 5. R. GREENBANK 2,626,265

METHOD AND APPARATUS FOR SOLVENT EXTRACTION Filed April 29. 1947 Patented Jan. 20, 1953 METHOD AND APPARATUS FOR SOLVENT EXTRACTION George Richard Greenbank, Piqua, Ohio, assignor to The French Oil Mill Machinery Company,

Piqua, Ohio Application April 29, 1947, Serial No. 744,747

(Cl. Mm -412.8)

8 Claims.

This invention relates to a novel and useful method for the solvent extraction of oil or fat from oil bearing vegetable and animal materials. Primarily the invention is directed to an improved method and means for filling the drainage baskets in extractors of the conventional paternoster type, and for the subsequent application of liquid solvent to the oil bearing material to achieve better solvent drainage and more complete extraction of the oil. Extraction apparatus of the type to which the invention particularly relates are disclosed, for instance, in U. S. Patent #2,225,799 to H. S. Robinson, dated December 24, 1940, and in the application for U. S. patent of Bert B. Beeson, filed November 30, 1945, Serial #713,377 now Patent- No. 2,512,710.

In the method of solvent extraction previously used, the solvent or miscella was sprayed on the flaked oil bearing material in such a manner that the flakes were continually subjected to a rain of solvent or miscella droplets. Such method obtained good extraction on some oil seeds whose flake structure was such that good drainage was obtained, but it resulted in causing the flakes to pack down and allow less drainage at the end of the cycle. I have found that dropping flakes into the solvent or miscella, and subsequently keeping them totally submerged during the extraction cycle, results in greatly improved drainage rates and more complete extraction.

My invention, which constitutes an improvement in the technique of solvent extraction especially applicable to continuous extractors or the paternoster baskettype, comprises the dropping of the oil bearing material in the form or condition of flakes into a container partially filled with solvent, and then pouring or delivering the slurry of flakes and solvent into the drainage baskets of the apparatus. By this means the baskets are filled more uniformly, flake spillage is reduced because all flakes are completely wetted down, and the flakes are introduced into the baskets in a manner that keeps them fiuifier and in a condition that permits more rapid solvent drainages and consequently more complete extraction. In combination with this novel method of basket filling, my improved method includes the subsequent application of solvent or miscella to the baskets in sufficient quantity and at a rapid enough rate to keep the flakes completely submerged in solvent. This subsequent application of the solvent Or miscella combined with the described method of basket filling, I have found, results in the flake retention of a much superior porosity at the end of the extraction cycle. It

also results in an improved drainage rate and makes possible more complete or much. more rapid extraction.

An example of one embodiment or application of my invention follows, and is illustrated in the accompanying drawing. It is to be understood that the particular means herein disclosed and illustrated as an example'are not intended to limit my invention or discovery, which is set forth in the appended claims.

Referring to the drawing, flakes of oil bearing material are delivered into a feed hopper I having a discharge passage in its bottom controlled by pivoted discharge gates 2 which move into the dash line positions when discharging. Disposed below the hopper is a liquid holding container or drum 3, pivoted on shaft 3a, and having an open face 317 beneath the hopper when the drum is upright, as shown, but pouring the contents of the drum, when the drum is rotated, on shaft 3a into an inverted position. The drum 3 is disposed above one of the baskets 4 when the basket is in one position in its travel. Liquid solvent or miscella is first introduced intothe filling container or circular drum 3, as through a supply pipe 6, and then a charge of flakes dropped into it from the feed hopper. The flakes are wetted down by the miscella. As the drainage baskets 4 come in succession into position beneath the filling container 3, the latter is rotated by hand or mechanically, into inverted position above a basket, so that the slurry of flakes and solvent is poured from the container into the basket 4 in such a manner that no spillage occurs and a uniform flake distribution is obtained in the basket. At the same time, and also preferably after the slurry has been poured into the basket, additional solvent or miscella is added in the basket as through supply nozzles I, so that the flakes are always submerged in solvent and the buoyancy of the solvent is used to continually keep the flakes loose and in condition to allow rapid drainage.

The merits of this method are evident on all or most all oil seeds, but give particularly unexs pected improvement in the extraction of oil seeds which form inferior flakes.

I claim as my invention:

1. In an extractor of the type having travelling drainage baskets for extraction of oil from oil bearing material, a hopper and a liquid holding container disposed in superposed relation with the hopper uppermost and discharging solids into said container, and both disposed above one of said baskets in one position of the travel, a pipe disposed to direct a liquid solvent into the container, whereby a quantity of solvent may be placed in said container and a batch of said material discharged into the solvent in said container to be fully wetted thereby, said container being invertible to deliver the slurry of said solvent and submerged flakes as an entirety into said one basket while in said position, and a pipe disposed to direct solvent to the basket to maintain submergence of the flakes in the solvent during the extraction.

2. In a continuous extraction apparatus of the type having travelling drainage baskets for extraction of oil from oil bearing material, the combination of a feed hopper, an upright, liquid holding container located beneath said hopper for receiving therefrom a batch of said material by gravity, a pipe disposed for introducing a liquid solvent into said container, whereby flakes of the oil bearing material may be dropped into said container having therein a charge of solvent to submerge the flakes in the solvent, said container being shiftable to deliver the solvent and submerged flakes into one of the baskets, and a pipe disposed to direct additional solvent to the basket to maintain submergence of the flakes in the solvent during the extraction.

3. In a continuous extraction apparatus of the type having travelling drainage baskets with drainage bottoms for extraction of oil from oil bearing material, the combination of afllling hopper having a discharge passage at its bottom, a circular drum arranged to receive flakes of oil bearing material by gravity from said hopper passage, a pipe for introducing a liquid solvent into said drum, said hopper having a gate at its said passage operable to drop flakes of the oil bearing material into the solvent in said drum for submerging the flakes in the solvent, said drum being rotatableinto inverted position to empty the solvent and flakes therefrom by gravity into a drainage basket at a position in its travel,

, and a pipe for directing additional solvent into said basket to maintain submergence of the flakes in the solvent throughout the extraction.

4. In a continuous extraction apparatus of the type having drainage baskets arranged to travel in a cycle for extraction of oil from oil bearing material, the combination of a filling hopper, a drum movably mounted beneath said hopper, a supply pipe for introducing a liquid solvent into said drum, said hopper being operable to discharge a batch of flakes of the oil bearing material together into the solvent in said'drum for submerging the flakes in the solvent, said drum being disposed to receive the batch of flakes from said hopper and operable to deliver the solvent and submerged flakes into a drainage basket during its travel, and another pipe for applying solvent to the baskets to maintain complete submergence of the flakes in the solvent throughout the extraction.

5. An extractor of the type having a travelling drainage basket for extraction of oil from oil bearing materials comprising said basket having an apertured bottom, a hopper disposed at a level above the basket when in one position in its travel and having a movable bottom to discharge a batch of solids therefrom, a liquid holding container disposed beneath said movable bottom to receive said batch from said hopper, pipe means for discharging a solvent liquid into said con= tainer, said container being rockable to discharge its contents of solids and solvent liquid into said basket when the latter is in said position, and additional pipe means for discharging further solvent liquid upon themixture in said basket while it is in said position.

6. An extractor of the type having a travelling drainage basket for extraction of oil from oil bearing materials, comprising said basket having an apertured bottom, a hopper disposed at a level above the basket when in one position in its travel and having a movable bottom to discharge a batch of solids therefrom, a liquid holding container disposed beneath said movable bottom to receive said batch from said hopper, pipe means for discharging a solvent liquid into said container, said container being rockable to discharge its contents of solids and solvent liquid into said basket when the latter: is in said position, and additional pipe means 'for discharging further solvent liquid .upon the mixture in said basket in a plurality of itslpositions during its travel.

7. In the extraction of oil from oil-bearing solids by the paternoster principle, the improved method which comprises discharging in succession measured charges of said solids in flake form from a hopper, one at a time disposing a liquid holding container, of a size to hold about one of said charges, with its open face beneath the discharge of said hopper, moving drainage baskets in succession approximately beneath said container, depositing into said container with each charge a quantity of solvent sufficient to fully wet one of said charges, then discharging all of each charge of the solids and solvent from said container into the drainage basket then beneath it, and then discharging further solvent upon the solids in each of said baskets.

8. In the extraction of oil from oil-bearing solids in flake form, the combination of a hopper, a non-travelling, liquid-holding container disposed below the hopper to receive and hold charges of said solids, and a series of drainage baskets arranged to move in sequence beneath said container to receive in each the contents of said container in one batch, by gravity, a pipe arranged to discharge a quantity of solvent into said container before a batch is discharged into the container, and another pipe disposed to discharge further solvent upon the batch in each of said filled baskets in succession.

GEORGE RICHARD GREENZBANK.

REFERENCES CITED The following references are of record in the file of this patent:

, UNITED STATES PATENTS Number 518,324 Great Britain Feb. 2? 1940 

1. IN AN EXTRACTOR OF THE TYPE HAVING TRAVELLING DRAINAGE BASKETS FOR EXTRACTION OF OIL FROM OIL BEARING MATERIAL, A HOPPER AND A LIQUID HOLDING CONTAINER DISPOSED IN SUPERPOSED RELATION WITH THE HOPPER UPPERMOST AND DISCHARING SOLIDS INTO SAID CONTAINER, AND BOTH DISPOSED ABOVE ONE OF SAID BASKETS IN ONE POSITION OF THE TRAVEL, A PIPE DISPOSED TO DIRECT A LIQUID SOLVENT INTO THE CONTAINER, WHEREBY A QUANTITY OF SOLVENT MAY BE PLACED IN SAID CONTAINER AND A BATCH OF SAID MATERIAL DISCHARGED INTO THE SOLVENT IN SAID CONTAINER TO BE FULLY WETTED THEREBY, SAID CONTAINER BEING INVERTIBLE TO DELIVER THE SLURRY OF SAID SOLVENT AND SUBMERGED FLAKES AS AN ENTIRETY INTO SAID ONE BASKET WHILE IN SAID POSITION, AND A PIPE DISPOSED TO DIRECT SOLVENT TO THE BASKET TO MAINTAIN SUBMERGENCE OF THE FLAKES IN THE SOLVENT DURING THE EXTRACTION.
 7. IN THE EXTRACTION OF OIL FROM OIL-BEARING SOLIDS BY THE PATERNOSTER PRINCIPLE, THE IMPROVED METHOD WHICH COMPRISES DISCHARGING IN SUCCESSION MEASURED CHARGES OF SAID SOLIDS IN FLAKE FORM FROM A HOPPER, ONE AT A TIME DISPOSING A LIQUID HOLDING CONTAINER, OF A SIZE TO HOLD ABOUT ONE OF SAID CHARGES, WITH ITS OPEN FACE BENEATH THE DISCHARGE OF SAID HOPPER, MOVING DRAINAGE BASKETS IN SUCCESSION APPROXIMATELY BENEATH SAID CONTAINER, DEPOSITING INTO SAID CONTAINER WITH EACH CHARGE A QUANTITY OF SOLVENT SUFFICIENT TO FULLY WET ONE OF SAID CHARGES, THEN DISCHARGING ALL OF EACH CHARGE OF THE SOLIDS AND SOLVENT FROM SAID CONTAINER INTO THE DRAINAGE BASKET THEN BENEATH IT, AND THEN DISCHARGING FURTHER SOLVENT UPON THE SOLIDS IN EACH OF SAID BASKETS. 